Be Cautious About Topamax Pregnancy Risk, Headache Group Tells Women

The American Headache Society says women of childbearing age should be careful about using Topamax (topiramate) to treat migraine headaches because of its birth defect risk. The society’s advice followed the Food & Drug Administrationâ€™s (FDA) recent warning that women who take Topamax while pregnant are 20 times more likely to give birth to a child with a cleft lip or cleft palate.

Topamax, made by Johnson & Johnson, is an anticonvulsant medication approved for use alone or with other medications to treat patients with epilepsy who have certain types of seizures. Topamax is also approved for use to prevent migraine headaches. The FDA estimates that approximately 32.3 million prescriptions for Topamax or a generic equivalent were issued from January 2007 through December 2010.

Last month, the FDA changed the pregnancy classification for Topamax from Category C to Category D after data from the North American Antiepileptic Drug (NAAED) Pregnancy Registry indicated that mothers who were on topiramate during the first trimester of pregnancy had an increased risk of infants born with oral clefts. The new classification also applies to generic forms of Topamax.

The Pregnancy Category D designation means that there is positive evidence of human fetal risk based on human data, but the potential benefits of Topamax in pregnant women may outweigh the risks in certain situations.

The NAAED Pregnancy Data indicated that between one and two of every 100 infants (1.4%) who were exposed to Topamax in utero were born with a cleft lip or palate, compared to 3-5 of every 1000 infants (0.38-0.55%) born to mothers taking other antiepileptic medications during pregnancy, and 7 of every 10,000 infants (0.07%) born to mothers who neither had epilepsy nor took antiepileptic medications. According to the FDA, data from the United Kingdom Epilepsy and Pregnancy Register supported the North American AED Pregnancy Registry data.

Cleft lips and cleft palates occur when parts of the lip or palate do not completely fuse together early in the first trimester of pregnancy, a time when many women do not know they are pregnant. In most cases, children have to undergo surgery to correct the problem.

The American Headache Society advises that women of childbearing age carefully weigh the risks and benefits of Topamax when choosing a migraine treatment. The organization also points out that Topamax can impact the efficacy of certain contraceptives that contain estrogen. As such, women should discuss with their physicians alternative options for contraception while on topiramate to avoid unplanned pregnancies. Barrier birth control methods are probably safest, but progesterone-only pills, non-hormonal or progesterone-based IUDs, and progesterone injections/Depo-Provera are also choices to consider, the group said.